Optimization of RB5 Effluent Decolorization Efficiency Using KCT Composites - Statistical Approach with ANN Modeling

Calcined Kaolin / Calcium carbonate / TiO2 (KCT) composites were prepared using 1:1:1 and 1:1:2 proportions at 1000 °C calcination temperature.  The efficiency of KCT composites on the decolorization of Reactive Black 5 (RB5) effluent was investigated based on the composite concentration, pH, and time of treatment. Box and Behnken experimental design was used to optimize the decolorization efficiency of RB5 using KCT composites, followed by modeling of the treatment using an artificial neural network. Optimized parameters based on the Box and Behnken design for 1:1:1 KCT composites resulted in a decolorization efficiency of 94.5 %, using 20 g/L composites treated at pH 3 for a treatment duration of 3 hours 48 minutes. Similarly, for 1:1:2 KCT composites, 94 % decolorization efficiency of RB5 effluent has been achieved using 18.9 g/L composite treated at pH 3.5 for a treatment duration of 3 hours 56 minutes. Experimental results and the predicted results show close conformity in decolorizing RB5 effluents using KCT composites. Physico-chemical treatment of dyes using KCT composites was found to be efficient due to the formation of calcium silicate and calcium titanate, resulting in a strong photocatalytic adsorbent, leading to physical sorption and photochemical oxidation.